It is known in the prior art that windshield washer preparations are fluids carried by motor vehicles used for removing solid debris, cleaning windshield grime and deicing the windshield glass. Windshield washer preparations are used with the wiper blades while the vehicle is either stationary or in motion. Windshield washer fluid is sold in many formulations, and some may require dilution before being applied, although most solutions available in North America come premixed with no diluting required.
Automobile wash systems operate by pumping a small jet of fluid from a nozzle over the area of windshield glass contacted by the windshield wipers. The washer preparation, wiper arm and application nozzle system are also used on rear view windows, headlamps and on-board cameras. These wiper systems are also used on trains, aircraft, watercraft and other types of windscreens that need immediate cleaning. Windshield washer preparations are crucial for removing obscuring material from the windshield so the vehicle can be operated safely.
Washer preparations assist the windshield wipers as the wiper bar removes vision obscuring materials from the from the driver's line of sight. Vision obscuring materials include dirt, grime, insect material, pollen, sap, road-tar, oil, frost, ice, snow and combinations thereof. These materials are mixed with various amounts of turgid water impinging the windshield from weather or road related sources. The adhesive force of obscuring materials greatly varies depending on the temperature of the windshield surface and the ambient temperature of the surrounding air.
Vision obscuring materials can be broken down into four specific groups. The first group consist of the different forms of water, which include ice, snow, sleet, hail, salt water sprays, turgid water and any other combination impinging the windshield. The second group consists of inorganic compound that include grime, oils, road tars, rock dust, fine sand and other materials associated with roadways. The third group included organic materials associated with bug impacts, bird droppings, farm dirt, pollen, tree sap and other compounds associated with the driving locale that may impinge the windshield. Organic compound largely consist of proteins, sugars, lipids and complex carbohydrates. The fourth group includes waxes, polymers and other compounds used for automobile care that reduce driver visibility.
A traditional windshield washer composition contains 18% to 49% by volume methanol with the balance being water, a small amount of surfactant and a small amount of colorant. That fluid has an expected freezing point of −15° C. to −40° C. Traditional cleaners for automotive applications, although they are satisfactory in removing inorganic soils from hard surfaces, are often unsatisfactory in removing organic soils. In order to address all four categories, windshield washer preparation must not only remove both organic and inorganic materials, but also act as an antifreeze and ice remover.
A washer preparation that may be effective at above freezing temperatures may be ineffective at temperatures below freezing. In particular, combined mixtures of water and organic materials impinging the windshield at low temperatures are particularly difficult because the material becomes highly viscous. For example, drilling mud can have a kinematic viscosity 3 to 4 cSt. at 20° C., while at 0° C., the same materials have viscosity 7 to 18 cSt. As a reference, liquid water has a viscosity of 0.894 cSt.
The less effective washer preparations make removing vision obscuring materials difficult and will cause undesired delays due to the time it takes to remove the material. All vehicle operators' benefit from a windshield washer preparation that reduced the amount of undesired delays, the amount of windshield washer fluid used and the amount of mechanical action necessary to restore clarity to the windshield.
Another method for removing organic soils from automotive surfaces involves the use of compositions containing enzymes. The reaction time for enzyme for dissolving lipids and proteins deposited by insect strikes are long. Tree sap, pollen and pine tar require alternative solvents capable of quickly removing these materials.
Windshield washer fluid makers have also reformulated preparations with low volatile organic compounds (“VOC”). In some regions of the United States, this limit can be as low 1% VOC's by weight. Thus, a problem currently facing manufacturers of windshield washer preparations is the need to comply with the new VOC restrictions while, at the same time, maintaining cleaning effectiveness. This problem is especially significant with respect to cleaning products for automotive applications.
Washer preparations may sometimes be preheated before being delivered onto the windshield. This is especially desirable in colder climates when a thin layer of ice or frost accumulates on the windshield's surface, because it eliminates the need to manually scrape the windshield or pour warm water on the glass. Although there are some after market preheat devices available, many automobile makers offer this feature factory installed on at least some of their vehicles. Different system patented alternately spray standard washer fluid and a strong de-icing formulated washer fluid on to the windscreen.
There is a need for a preparation to aggressively remove protein and lipids from the hard surface of a windshield over a range of temperatures. There is a need for a preparation to remove organic gums, tars and pollens over a range of temperatures that accumulate on vehicle surfaces. There is a need for a preparation to remove grime and debris without causing surface paint damage. There is also a need for a preparation that can meet the volatile organic limits in various jurisdictions.
It is another objective that the process used to produce the cleaning preparation can also produce a propellant that can be used with the windshield washer preparation. It is another objective of the invention to package the cleaning preparation in containers at pressures of 1 bar or at pressures above 3 bar to 6 bar using a propellant produced during the process used to produce the washer preparation. It is also the objective that the propellant is water-soluble.